/Engine/Plugins/FX/Niagara/Source/Niagara/Public/NiagaraSpriteRendererProperties.h
This enum decides how a sprite particle will orient its "facing" axis. Must keep these in sync with NiagaraSpriteVertexFactory.ush
enum ENiagaraSpriteFacingMode { FaceCamera, FaceCameraPlane, CustomFacingVector, FaceCameraPosition, FaceCameraDistanceBlend, Automatic, }